Real-time and integrated measurement of potential human exposure to particle-bound polycyclic aromatic hydrocarbons (PAHs) from aircraft exhaust

We used real-time monitors and low-volume air samplers to measure the poten tial human exposure to airborne polycyclic aromatic hydrocarbon (PAH) conce ntrations during various flight-related and ground-support activities of C- 130H aircraft at an Air National Guard base. We used three types of photoel ectric aerosol sensors (PASs) to measure real-time concentrations of partic le-bound PAHs in a break room, downwind from a C-130H aircraft during a fou r-engine run-up test, in a maintenance hangar, in a C-130H aircraft cargo b ay during cargo-drop training, downwind from aerospace ground equipment (AG E), and in a C-130H aircraft cargo bay during engine running on/off (ERO) l oading and backup exercises. Two low-volume air samplers were collocated wi th the real-time monitors for all monitoring events except those in the bre ak room and during in-flight activities, Total PAH concentrations in the in tegrated-air samples followed a general trend: downwind from two AGE units > ERO-loading exercise > four-engine run-up test > maintenance hangar durin g taxi and takeoff > background measurements in maintenance hangar. Each PA H profile was dominated by naphthalene, the alkyl-substituted naphthalenes, and other PAHs expected to be in the vapor phase. We also found particle-b ound PAHs, such as fluoranthene, pyrene, and benzo[a]pyrene in some of the sample extracts. During flight-related exercises, total PAH concentrations in the integrated-air samples were 10-25 times higher than those commonly f ound in ambient air. Real-time monitor mean responses generally followed th e integrated-air sample trends. These monitors provided a semiquantitative temporal profile of ambient PAH concentrations and showed that PAH concentr ations can fluctuate rapidly front a baseline level < 20 to > 4,000 ng/m(3) during flight-related activities. Small handheld models of the PAS monitor s exhibited potential for assessing incidental personal exposure to particl e-bound PAHs in engine exhaust and for serving as a real-time dosimeter to indicate when respiratory protection is advisable.